1. Field of the Invention
This invention relates to a programmable logic controller coupler that couples to an ETHERNET network under TCP/IP protocol in order to communicate with various equipment.
2. Discussion of the Background
Traditionally, an automation system is segmented into several levels. The lower level contains the sensors/actuators bus that enables exchanges between programmable logic controllers or numerical controls and sensors and actuators associated with them. At a higher level there is a computer type bus that connects computers responsible for supervision and the information system on the production site. There are buses at an intermediate level that form the junction between the previous levels.
It is known how to use the TCP/IP protocol and software adapted to this protocol for communications between the various levels of equipment on a PLC network, for example using an ETHERNET type bus. The programmable logic controllers are then equipped with a communication module or coupler that is coupled to an Internet or an Intranet type network using the TCP/IP protocol.
The purpose of this invention is to supply a programmable logic controller coupler using the ETHERNET, FTP, HTTP, TCP/IP technologies in order to host a WEB site accessible with a commercially available browser. It enables updates of system software, both in production and on the customer site, and can be used to customize a product range.
The system according to the invention is essentially characterized by the fact that it implements two disk partitions in flash memory, one acting as a disk for the real time operation system, the other acting as a user disk, access to these two disks being possible using the FTP protocol on TCP/IP, the user disk space being managed by an HTTP server.